sp. nov., an anaerobic, amino-acid-utilizing bacterium isolated from marine subsurface sediment.

A novel, anaerobic bacterium, strain MO-SEDI, was isolated from a methanogenic microbial community, which was originally obtained from marine subsurface sediments collected from off the Shimokita Peninsula of Japan. Cells were Gram-stain-negative, non-motile, non-spore-forming rods, 0.4-1.4 μm long by 0.4-0.6 μm wide. The cells also formed long filaments of up to about 11 μm. The strain grew on amino acids (i.e. valine, leucine, isoleucine, methionine, glycine, phenylalanine, tryptophan, lysine and arginine), pyruvate and melezitose in the presence of yeast extract. Growth was observed at 4-37 °C (optimally at 30 °C), at pH 6.0 and 8.5 (optimally at 7.0-7.5) and in 0-60 g l NaCl (optimally 20 g NaCl l). The G+C content of the DNA was 32.0 mol%. The polar lipids of strain MO-SEDI were phosphatidylglycerol, phosphatidyl lipids and unknown lipids. The major cellular fatty acids (>10 % of the total) were C, Cω9 and C dimethyl aldehyde. Comparative sequence analysis of the 16S rRNA gene showed that strain MO-SEDI was affiliated with the genus within the phylum . It was related most closely to the type strain of (94 % sequence similarity). Based on the phenotypic and genetic characteristics, strain MO-SEDI is considered to represent a novel species of the genus , for which the name sp. nov. is proposed. The type strain is MO-SEDI ( = JCM 17293 = DSM 24004).